To Prevent Leg Clots on Long Flights, Don’t Just Sit There

Planning a vacation this summer? If it means you’ll be sitting for long hours in a plane or car, you could be increasing your risk of developing dangerous leg clots.

Often called economy class syndrome, especially now that airlines are cutting down on legroom and squeezing in more seats, the actual medical term is deep vein thrombosis (DVT), for clots that form in deep veins, usually in the leg, due to immobility and poor blood circulation. Swelling, redness, warmth and pain are typical symptoms, although clots also can be symptomless.

The real trouble comes if a leg clot moves and travels to a vital organ, like the heart, brain or lungs. A clot that lands in the lungs, called a pulmonary embolism, can be life threatening. Pulmonary embolisms are the third leading cause of death in the U.S.; the type associated with DVT sends about half a million people to the hospital annually. One in 10 of those will die suddenly without diagnosis, according to the Centers for Disease Control and Prevention.

Risk factors for leg clots include being over 40, being obese and having undergone recent surgery. Even without these risk factors, however, long-distance plane travel can increase your risk significantly, medical experts say.

Awareness of DVT has grown since the well-publicized 2003 death of NBC Today show anchor David Bloom. Bloom, who was covering the war in Iraq, died suddenly when a blood clot in his leg – probably formed during his long days spent riding in cramped armored vehicles – traveled to an artery in his lungs. Other celebrities who have talked about their problems with DVT include race car driver Brian VickersÂ and tennis player Serena Williams, as well as talk show host Regis Philbin.

You can help prevent these dangerous clots by doing simple exercises and taking some precautions during a flight. Here are six things you need to know, from Omid Jazaeri, director of vascular surgery at the University of Colorado Hospital.

Your risk is highest on flights lasting more than eight hours. Even flights that are four to six hours present a risk. And don’t relax just because you’ve landed. “While most [clot] episodes occur within the first two weeks, with a median of four days, the risk is prolonged for up to four weeks after landing,” Jazaeri warns. Check your legs carefully for swelling, tenderness, skin that feels unusually warm, or redness. Symptoms of a lung clot include shortness of breath or chest pain; get help immediately.

Plane flights are riskier than long car or bus rides. It’s not just sitting for a long time that’s the problem, says JazaeriÂ –Â it’s those crowded seats, the low oxygen and dryness of the cabin air, and the tendency to become dehydrated, which causes the blood to become thick and sluggish. “Scientists have investigated this issue” by comparing a rise in pre-clotting levels in people who watched movies for eight hours versus thoseÂ who flew on a plane, he says. They found a 223 percent rise in the levels in air travelers, compared withÂ a 46 percent rise in the movie watchers.

Doing simple exercises keeps blood circulating. Obviously, getting up and walking is a good idea, but it can be difficult. Leg flexing exercises you can do in your seat are equally important because they getÂ blood circulating in the veins of the calf muscles, Jazaeri explains. Extend your legs, if possible, and flex your ankles, pulling up and spreading your toes, then pushing down and curling them. Rotate your ankles, making circles in the air. If you can’t extend your legs, place your feet flat on the floor; push down on your toes and lift heels five times. Then keep heels flat and lift toes five times. Do this every 30 minutes. Exercise your thigh muscles by sliding feet forward a few inches, then sliding them back; repeat.

Avoid caffeinated beverages and alcohol. Drink water or other non-caffeinated, nonalcoholic beverages to stay hydrated and keep blood from thickening. Sports drinks with electrolytes can be helpful, assuming you can find a place in the airport that sells them so you can bring them aboard.

Wear graduated compression stockings. Most experts agree that these can be helpful; just don’t confuse them with regular support hose, which can be harmful during a flight, Jazaeri says. The graduated hose are tightest at the ankles, growing less constrictive around the knees and thighs. This prevents blood from pooling in the lower legs and feet, and forces it toward the heart instead. Support hosiery is too constrictive.

Ask your doctor about a blood thinner injection. For those at high risk for a clot and not on blood thinners, your doctor might suggest a single injection of blood thinnerÂ before you travel, Jazaeri says. In most cases, though, doing leg exercises, staying hydrated and wearing graduated compression hose are the most effective preventive measures.